1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
|
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2013 NVIDIA Corporation
*/
#include <common.h>
#include <linux/err.h>
#include "mipi-phy.h"
/*
* Default D-PHY timings based on MIPI D-PHY specification. Derived from the
* valid ranges specified in Section 6.9, Table 14, Page 40 of the D-PHY
* specification (v1.2) with minor adjustments.
*/
int mipi_dphy_timing_get_default(struct mipi_dphy_timing *timing,
unsigned long period)
{
timing->clkmiss = 0;
timing->clkpost = 70 + 52 * period;
timing->clkpre = 8;
timing->clkprepare = 65;
timing->clksettle = 95;
timing->clktermen = 0;
timing->clktrail = 80;
timing->clkzero = 260;
timing->dtermen = 0;
timing->eot = 0;
timing->hsexit = 120;
timing->hsprepare = 65 + 5 * period;
timing->hszero = 145 + 5 * period;
timing->hssettle = 85 + 6 * period;
timing->hsskip = 40;
/*
* The MIPI D-PHY specification (Section 6.9, v1.2, Table 14, Page 40)
* contains this formula as:
*
* T_HS-TRAIL = max(n * 8 * period, 60 + n * 4 * period)
*
* where n = 1 for forward-direction HS mode and n = 4 for reverse-
* direction HS mode. There's only one setting and this function does
* not parameterize on anything other that period, so this code will
* assumes that reverse-direction HS mode is supported and uses n = 4.
*/
timing->hstrail = max(4 * 8 * period, 60 + 4 * 4 * period);
timing->init = 100000;
timing->lpx = 60;
timing->taget = 5 * timing->lpx;
timing->tago = 4 * timing->lpx;
timing->tasure = 2 * timing->lpx;
timing->wakeup = 1000000;
return 0;
}
/*
* Validate D-PHY timing according to MIPI D-PHY specification
* (v1.2, Section 6.9 "Global Operation Timing Parameters").
*/
int mipi_dphy_timing_validate(struct mipi_dphy_timing *timing,
unsigned long period)
{
if (timing->clkmiss > 60)
return -EINVAL;
if (timing->clkpost < (60 + 52 * period))
return -EINVAL;
if (timing->clkpre < 8)
return -EINVAL;
if (timing->clkprepare < 38 || timing->clkprepare > 95)
return -EINVAL;
if (timing->clksettle < 95 || timing->clksettle > 300)
return -EINVAL;
if (timing->clktermen > 38)
return -EINVAL;
if (timing->clktrail < 60)
return -EINVAL;
if (timing->clkprepare + timing->clkzero < 300)
return -EINVAL;
if (timing->dtermen > 35 + 4 * period)
return -EINVAL;
if (timing->eot > 105 + 12 * period)
return -EINVAL;
if (timing->hsexit < 100)
return -EINVAL;
if (timing->hsprepare < 40 + 4 * period ||
timing->hsprepare > 85 + 6 * period)
return -EINVAL;
if (timing->hsprepare + timing->hszero < 145 + 10 * period)
return -EINVAL;
if ((timing->hssettle < 85 + 6 * period) ||
(timing->hssettle > 145 + 10 * period))
return -EINVAL;
if (timing->hsskip < 40 || timing->hsskip > 55 + 4 * period)
return -EINVAL;
if (timing->hstrail < max(8 * period, 60 + 4 * period))
return -EINVAL;
if (timing->init < 100000)
return -EINVAL;
if (timing->lpx < 50)
return -EINVAL;
if (timing->taget != 5 * timing->lpx)
return -EINVAL;
if (timing->tago != 4 * timing->lpx)
return -EINVAL;
if (timing->tasure < timing->lpx || timing->tasure > 2 * timing->lpx)
return -EINVAL;
if (timing->wakeup < 1000000)
return -EINVAL;
return 0;
}
|